This invention relates to impacted teeth and, specifically, to a method and apparatus to facilitate placement of a system to aid in extrusion and positioning of such teeth. In general, the present invention is less invasive than previous products and methods of extruding impacted teeth, thus, making the extrusion of the tooth more comfortable for the patient. Another object of the invention is that it provides an easier, more comfortable removal of the apparatus used to extrude the impacted tooth from the surface of the tooth.
Treatment of an unerupted tooth generally involves both oral surgery to expose a significant portion of the impacted tooth and use of orthodontics to apply tension or traction to cause the tooth to erupt and bring the tooth into its proper position. Typically the orthodontics used to facilitate the extrusion of the tooth must be forcibly fractured off the surface of the tooth after it has been moved into the desired position. Such a removal process can be uncomfortable or even painful for the patient. Various products and methods have been developed to address this problem with varying levels of success.
One such apparatus and method of treatment is disclosed in U.S. Pat. No. 4,187,610, Ziegler, Feb. 12, 1980. Ziegler discloses use of a ligation chain that has a large loop at one end followed by a series of smaller loops. The large loop encircles and is tightened around the surgically exposed anatomic crown of the impacted tooth. The smaller loops are connected to an elastic ligature thread that is then attached to an arch wire, bracket, or similar conventional orthodontic apparatus to apply tension to the impacted tooth. One disadvantage of such an approach is that the oral surgeon must expose a significant amount of the impacted tooth to enable the ligation chain to be looped around the tooth below the crown, resulting in a rather invasive procedure for the patient. The wire looped around the tooth can also slip out of position during traction, possibly necessitating additional surgery. Additionally, the removal of the device involves cutting and pulling of the wire, causing patient discomfort.
Yet another approach involves bonding some type of fastener to the surface of the impacted tooth. Such an approach is disclosed in U.S. Pat. No. 3,835,538, Northcutt, Sep. 17, 1974; U.S. Pat. No. 7,335,021, Nikodem, Feb. 26, 2008; and U.S. Pat. No. 6,354,833, Townsend-Hansen, Mar. 12, 2002.
Northcutt discloses bonding a curved onlay to the surface of the impacted tooth that has a means to attach a ligature, such as a plastic loop, integrated in the onlay. However, Northcutt admits in col. 2, 1. 49-52 that the onlays will not fit the teeth of one-tenth of people, requiring correction of the shape of the onlay using a dental burr by the orthodontist or surgeon. Northcutt still requires exposure of about one-third of the cuspid crown for placement of the onlay (col. 1, 1. 46-47). Also, after the tooth has been erupted and moved into the desired position, the onlay must be forcibly removed or fractured from the surface of the tooth.
Nikodem similarly discloses use of an orthodontic fixture bonded to the surface of the impacted tooth as a means to attach a ligature. Such a fixture can include an orthodontic bracket. An example of an orthodontic bracket specifically used in extrusion of impacted teeth is disclosed in Townsend-Hansen. However, conventional brackets can cause irritation and can be difficult to precisely position and bond to the surface of an impacted tooth. Additionally, an intermediary mesh backing is typically associated with brackets to either carry adhesive or provide a bonding site. Failure of the bond can and often does occur at the contact point between the mesh and the surface of the tooth or the contact point between the mesh and the bracket or other orthodontic fixture. Fixtures or brackets such as those disclosed in Nikodem and Townsend-Hansen must be forcibly fractured off the surface of the tooth, causing significant patient discomfort.
U.S. Pat. No. 5,112,221, Terry, May 12, 1992 discloses an extrusion spring arm for facilitating the eruption of an impacted tooth. The arm has an eyelet that is bonded to the impacted tooth. However, the patent does not disclose specifically how the eyelet is bonded to the tooth, only that it is bonded on the tooth.
U.S. Pat. No. 5,829,368, Wolk, Oct. 13, 1998 and U.S. Pat. No. 5,681,163, Wolk, Oct. 28, 1997 disclose-disposable applicators for bonding and retaining orthodontic attachments, such as wires, to the front or back surface of fully erupted teeth. The orthodontic attachments are described as wires or conventional brackets or rubber bands to correct the irregular teeth of the patient.
The present invention addresses these problems by requiring only minimal access to the surface of the impacted tooth, enabling adhesive to conform to any tooth's surface and being easily removable after eruption and positioning of the tooth.